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Green Area Ratio (GAR) Sign-Off by an ISA Certified Arborist in DC

Green Area Ratio is easiest, and least expensive, when it is planned at the start of a project alongside the trees already on the site. When GAR is left until drawings are finished, it usually shows up as a late redesign, a squeezed-in green roof, or a Certificate of Occupancy that cannot be released.

Todd Krellner is an ISA Certified Arborist, one of the credentials DOEE accepts for a Certified Landscape Expert (CLE). That means DMV Horticulture can review and sign your GAR plan, coordinate it with your Tree Preservation Plans, and sign the final GAR Landscape Checklist with the DOEE inspector at the end of construction.

Native-planted green roof installed on a Washington, DC project for Green Area Ratio credit
Green roof with 8 inches of soil and native plantings on a DC GAR project

Why GAR Gets Expensive When It Comes Late

DOEE tells developers to consider GAR landscape features at the beginning of project development. Once the building footprint, grading, and stormwater design are locked, the remaining options to reach the required score are usually the costly ones.

  • GAR plans are submitted to DOEE’s Surface and Groundwater System (SGS) with the foundation-to-grade or building permit, so they need to be ready early.
  • A Certified Landscape Expert must review and sign the plan before it is submitted.
  • The final Certificate of Occupancy is not granted until the signed GAR Landscape Checklist reaches the Office of the Zoning Administrator.

Preserved Trees Count Toward Your GAR Score

Keeping existing trees is not only a tree-law requirement. On the DC GAR scoresheet, preserved trees carry a higher multiplier than new plantings: 0.7 for preserved trees 6 to 24 inches in diameter and 0.8 for preserved trees 24 inches or larger, compared with 0.5 to 0.6 for new trees.

That is why we plan tree preservation and GAR together. A tree that is protected properly during construction can help satisfy both DDOT’s tree requirements and your GAR score, and reduce how much new green roof or other landscape area the project has to buy.

What We Provide

  • Early site review to identify trees worth preserving and how they affect your GAR strategy
  • Coordination of the GAR plan with your Tree Preservation Plan, civil, and stormwater design
  • Certified Landscape Expert review and signature for SGS submission
  • Landscape maintenance plan, signed by the CLE
  • Construction-phase checks that GAR elements and preserved trees match the approved plan
  • Final GAR inspection with the DOEE inspector and electronic Landscape Checklist sign-off in SGS
Permeable paver gravel base installation for Green Area Ratio credit in Washington, DC
Permeable paver base installation on a DC GAR project

Our Process

  1. Early review. We look at the site, the trees, and the zone’s required GAR score before drawings are finalized.
  2. Plan coordination. We work with your architect and engineer so preserved trees and landscape elements reach the required score efficiently.
  3. CLE sign-off. We review and sign the GAR plan for submission with your permit.
  4. Construction and final inspection. We confirm the work matches the approved plan, attend the final GAR inspection with DOEE, and sign the Landscape Checklist so your Certificate of Occupancy can move forward.

Green Area Ratio: Frequently Asked Questions

Can an ISA Certified Arborist sign GAR plans?

Yes. DOEE lists the ISA Certified Arborist credential among those that qualify as a Certified Landscape Expert for GAR plans and the final Landscape Checklist.

When are GAR plans submitted?

For new buildings, GAR plans are submitted through DOEE’s Surface and Groundwater System with the foundation-to-grade or building permit, so they can be coordinated with stormwater review.

What happens at the end of construction?

The Certified Landscape Expert and the DOEE inspector complete a final GAR inspection. Once the inspector confirms the landscape elements match the approved plan, both sign the Landscape Checklist, which is required before the final Certificate of Occupancy is issued.

Does my project need GAR?

GAR applies to many new buildings and major additions in DC, and the minimum score depends on the zone. DOEE also publishes exemptions. Send us the address and scope and we will help you confirm whether GAR applies.

Get In Touch Today

Call or text 443-934-0871, or email toddk@dmvhorticulture.com. Bring us in before drawings are final and we will plan tree preservation and GAR together.

Or send your project details below and Todd will follow up.